JPS6076784A - Destaticizer - Google Patents

Abstract

PURPOSE:To control the potential right after the electrostatic charge of a photosesitive body so as to attain a prescribed size in the stage of the initial destaticization after pause for prescribed or longer time by providing a control circuit which makes the quantity of light of a destaticizing lamp smaller than the ordinary quantity. CONSTITUTION:A dimmer 16 is controlled by a controller 15 and the quantity of light of a destaticizing lamp 2 is changed so that the dark potential of a photosensitive body 1 electrostatically charged by an electrostatic charge corotron 3 attains prescribed magnitude after destaticization by the lamp 2. The quantity of the light of the lamp 2 is changed in the first destaticization after pause for specified or longer time, by which the dark potential of the body 1 is maintained always at the prescribed magnitude. The time for discharging the 1st sheet of recording paper after throwing of a power source is thus reduced and the body 1 is kept free from unnecessary stress.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a static eliminator used in an electrophotographic copying machine, and particularly to a static eliminator that sets the potential value of the surface of a photoreceptor that is charged after static neutralization to a predetermined value. Regarding.

[Prior art]

Electrophotographic copying using an organic photoreceptor (good is as shown in FIG. 1, in which the soil is irradiated as the photoreceptor drum 1 rotates,
After completely eliminating the charge, a charging corotron 3 applies charges to the surface of the photoreceptor drum 1 at a predetermined charge density, and then the document 5 placed on the platen 4 is irradiated with light from a light source 6. The reflected light 7 at this time is made to enter the photoreceptor drum 1 through an optical system composed of reflections 8a and 8b and a condenser lens 9, and a static image corresponding to the image information of the original 5 is placed on the surface of the photoreceptor drum 1. Forms an electrolatent image.

Then, this electrostatic latent image is visualized by a developing device 10, and the resulting l-toner image is transferred by a transfer corotron 11 to a paper 12 to which %LWI has been applied. Thereafter, the photoreceptor drum 1 after the transfer and the residual toner on the surface of the photoreceptor drum 1 are electrically neutralized by the static eliminating corotron 13, and the residual toner on the surface of the photoreceptor drum 1 is further removed by the cleaning device 14. This allows the photosensitive drum 1 to be used repeatedly. As described above, the copying machine performs the cleaning air at the cleaning device 14 from the static elimination process by the static elimination run f2.
By the way, the first photoreceptor drum 1 that is repeatedly used is 1ift history of shooting or blocking 11a, so-called light j11
Although the sensitivity differs depending on the mouse, Fig. 2 shows the light 1fj? Removed the photoreceptor drum 1 that has a history.
.

It is a graph showing the change in the electric charge r, that is, the dark 5, immediately after the photoreceptor drum 1 is charged when static elimination by the lump 2 and charging by the charging corotron 3 are 7 fi'li L. The photoreceptor drum 1 having a light (, Bf history) is activated during the first copy cycle (first
It has the property that the dark potential in the first copy cycle is lower than the dark potential in the previous copy cycles (second and subsequent copy cycles) before the pause time elapses.

To avoid this, conventionally, the first copy cycle after the above-mentioned pause time has elapsed is a dead cycle, and only static electricity removal by the static elimination ramp 2 and charging by the charging corotron 3 are performed.
I started listening to it for the first time from the next copy cycle.

Still, the start position of one copy cycle, which originally starts from the portion S below the surface of the static elimination lamp ``2'' of the photoreceptor drum 1, is set to the portion S' immediately below the transfer corotron 11, and the photoreceptor 1゜ram is moved by the transfer corotron 11. 1 until the portion S' reaches directly below the static eliminating lamp 2 is defined as a pseudo cycle, and it is treated as if one copy cycle has been completed.

However, when the dead cycle is provided, there is a problem that the recording paper ejection time becomes long.

Unfortunately, when the above-mentioned pseudo cycle is provided, there is a problem in that the movement of carriers within the photosensitive drum 1 causes stress to be applied to the drum 1, shortening its lifespan.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a static eliminator that neutralizes a photosensitive drum so that the potential of the photosensitive drum immediately after being charged reaches a predetermined level.

[Structure of the invention]

Therefore, in the present invention, by utilizing the fact that the potential of the photoreceptor to be charged changes depending on the irradiance of the light irradiated to the photoreceptor before the charging, at least the first charge removal after a rest period of a predetermined time or more has elapsed. In this case, the static eliminator is configured so that the light amount M of the static eliminator lamp is smaller than the normal light amount.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 is a side view of a copying machine equipped with a static eliminator according to the present invention. Parts that perform the same functions as those in FIG.

The controller 15 controls the dimmer 16 so that the dark potential of the photoreceptor drum 1 charged by the charging corotron 3 after static elimination by the static elimination run f2 is always at a predetermined level.
This is to change the amount of light from the static elimination lamp 2.

Next, the operation of the static eliminator according to the present invention will be explained with reference to the graph shown in FIG. 4 showing changes in the dark potential of the photosensitive drum 1 with respect to the number of copy cycles.

The controller 15 finally removes the photosensitive drum 1.
1 -r -^, r-rG Gri /711+, L
l1ja IIJI l soto Jl-%,'M l
fr 2a θ) M-In the case of the February copy cycle (first copy cycle), the copy cycle (before the pause time has elapsed) is set so that the radiation emittance of the static elimination lamp 2 is 500 μW/cm2. (from the second copy cycle onward), the radiation emittance of the static elimination lamp 2 is set to 1600.
(Produce a dimmer 16 to set it to 11A'/cm2).

The K'Q light device 16 drives the static elimination lamp 2 to emit light onto the photoreceptor drum 1 to completely eliminate the charge from the photoreceptor drum 1.
I℃.

The neutralized photosensitive drum 1 is charged by a charging corotron 3 . At this time, the dark potential of the photoreceptor drum 1 is a predetermined value of 1000V regardless of the IMI in the copy cycle calculation.
Becomes (Usazu 4 Tomoteru).

The static elimination lamp 2 may be a fluorescent lamp, a tungsten halogen lamp, or a sodium lamp 0, as long as it can change the amount of light.

[Effects of the Invention] As explained above, according to the division t+g device i according to the present invention, the dark potential of the photoreceptor drum can always be kept at a predetermined level by changing the amount of light irradiated onto the photoreceptor drum. This makes it possible to shorten the time it takes to eject the first sheet of recording paper after power is turned on.

Still, since no unnecessary stress is applied to the photoreceptor 1 ram, a reduction in the life of the photoreceptor can be prevented.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a general example of Ichikoji/i photocopying, Fig. 2 is a graph showing changes in dark potential corresponding to copy cycles of a photoreceptor drum with a bright layer, and Fig. 3 is an explanatory diagram of a sample equipped with an apparatus bar according to the present invention (explanatory drawing of the sample shown in FIG. This is a graph. 1... Photoconductor drum, 2... Static elimination rung, 3 Band ji.
Mokorotron, 4...)0 Latin, 5...Ima'If4
．． 6... Light source, 7... Reflected light, 8i, 8b... Reflecting mirror, 9... Condensing lens, 10... Current 13゛ device, 1
DESCRIPTION OF SYMBOLS 1... Transfer corotron, 12... Paper, 13... Static elimination corotron, 14... Cree, =yg device, 15...
... Controller, 16... Dimmer.

Claims (1)

[Claims] In a static eliminator that irradiates a photoreceptor with light to eliminate residual charges, a static eliminator lamp that irradiates the photoreceptor with light;
A static eliminator 5 device comprising a static eliminator control circuit that reduces the light intensity of the static eliminator lamp to be lower than the normal light intensity during at least the first static neutralization after a pause time of a predetermined period or more has elapsed.